When I’m in the car my Bluetooth hearing aids take over any phone calls and then I’m the only one who can hear the phone c

[the.twit18]

Bluetooth bearing aids

 

[Ralston18]

You should be able to pair multiple Bluetooth devices with your car.

To be honest (full disclosure) I have not heard of "Bluetooth hearing aids" per se.

Overall, I would expect that incoming phone calls would go to the connected "Bluetooth" phone per se and not the hearing aids.

What make and model car do you have?

You may need dealer assistance to set up and prioritize the Bluetooth configuration with respect to hearing impairments.

 

[SkyBill40]

I would think you'd have to manually pair your hearing aids to the phone as it won't happen automatically. The same would go for your head unit in the car. The only thing I could think of would be to unpair your hearing aids from the phone so that the pairing with the car's head unit would take over instead and then re-pair them once you're out of the car.